海坛海峡海缆路由区工程地质条件及评价

根据路由勘察区水深测量、旁侧声纳、浅地层剖面探测等多项物理探测所获取的资料，结合其它自然环境及历史资料，对勘察区内海底工程地质条件进行了详尽的分析和研究．此外，还对近20a来勘察区海床稳定性进行初步分析，为选择一条最佳的路由通道提供依据．研究分析表明：可能影响该海缆安全运行的不良工程地质条件主要为海底灾害性地貌，如基岩、潮流冲刷槽等；勘察区不同区域内海底冲淤变化存在一定差异，潮汐通道底部受较强冲刷，冲刷速率为0．035～0．1m／a，20m以浅区域海底处于弱冲刷状态一冲淤动态平衡状态，冲刷速率为0．015m／a，海床较稳定；该路由勘察区工程环境较适合海缆的铺设，且其最佳路由区域是在勘察区南半部相对稳定的海底平滑区．

Evaluation of the engineering geology condition in Haitan Strait in Fujian,China

Based on the data from echo-sounder, side scan sonar and subbottom profiler in the route of survey area, from natural environment investigations and from historical records, the submarine engineering geologic conditions in the route area are analysed. In addition, the stability of the seabed in the route area was analysed using data of recent 20 years in order to select an optimal route channel. The results show that the adverse submarine engineering geologic condition can be affected by disastrous seabed topography, i. e. seabed rocks and erosion trench. It is also indicated that the bottom of the tidal channel has been scoured severely and the scouring rate is 0.035 - 0.1 m/a. At other sites where water depth is shallower than 20m, the seabed is in a steady state with weak scouring rate of 0. 015m/a. As result,the optimal route channel is located in areas in the south where the geologic condition is relatively stable and submarine surface is smooth.